The time-resolved and time-integrated spectra of fluorescence in Ar/He/F2 mixtures excited by fast discharge were measured. By measuring the ratio of ArF* and Ar3F* time-integrated intensities, the three body formation rate constants of Ar2F*, as well as the quenching coefficient of Ar2F* by F2 were obtained. The two-body formation reaction of Ar2F* via Ar2* and ion-ion recombination formation process of Ar2F* are aslo discussed.